<template>
  <div class="star" :class='starType'>
    <span v-for="item in itemClass" :class='item' class='star-item' :key='item.index'></span>
  </div>
</template>

<script type="text/ecmascript-6">
  const LENGTH = 5
  const CLS_ON = 'on'
  const CLS_HALF = 'half'
  const CLS_OFF = 'off'

  export default{
    props: ['size', 'score'],
    computed: {
      starType () {
        return 'star-' + this.size
      },
      itemClass() {
        let result = [] //  所有星星的数组
        let score = Math.floor(this.score * 2) / 2
        let hasDecimal = score % 1 !== 0
        let integer = Math.floor(score)
        for (let i = 0; i < integer; i++) {
          result.push(CLS_ON)
        }
        if (hasDecimal) {
          result.push(CLS_HALF)
        }
        while (result.length < LENGTH) {
          result.push(CLS_OFF)
        }
        return result
      }
    }
  }
</script>

<style lang='stylus' rel="stylesheet/stylus">
  @import '../../common/stylus/mixin'

  .star{
    font-size:0
    .star-item{
      display:inline-block
      background-repeat: no-repeat
    }
    &.star-48{
      .star-item{
        width:20px
        height:20px
        margin-right:22px
        background-size:20px 20px
        &:last-child{
          margin-right:0
        }
        &.on{
          bg-image('star48_on')
        }
        &.half{
          bg-image('star48_half')
        }
        &.off{
          bg-image('star48_off')
        }
      }
    }
    &.star-36{
      .star-item{
        width:15px
        height:15px
        margin-right:16px
        background-size:15px 15px
        &:last-child{
          margin-right:0
        }
        &.on{
          bg-image('star36_on')
        }
        &.half{
          bg-image('star36_half')
        }
        &.off{
          bg-image('star36_off')
        }
      }
    }
    &.star-24{
      .star-item{
        width:10px
        height:10px
        margin-right:3px
        background-size:10px 10px
        &:last-child{
          margin-right:0
        }
        &.on{
          bg-image('star24_on')
        }
        &.half{
          bg-image('star24_half')
        }
        &.off{
          bg-image('star24_off')
        }
      }
    }
  }
</style>
